Alternative history thrives on ignorance. I came across this fascinating bit of historical nonsense describing the ridiculous work of Augustus Le Plongeon, who imagined himself a reincarnated prince of Atlantis and thought that the Maya were coeval with Egypt and both equal sons of Atlantis. The following quotation comes from "A Monument to Atlantis," published in Mind magazine around the turn of the twentieth century.

A notable discovery of more than ordinary interest for historians, especially those who have a leaning toward antiquities, has lately been made by the well-known archaeologist, Augustus Le Plongeon. This discovery should particularly attract the attention of Americans, since it enables them to lay claim to one of the most important monuments of ancient times. The edifice in question is the Pyramid of Xochicalo, standing 5,396 feet above the level of the sea, and situated to the south-southwest of Cuernavaca, 60 miles from the City of Mexico. For more than a century the pyramid has been occasionally visited by distinguished travelers, including the learned Humboldt; but none succeeded in discovering the purpose for which the monument had been erected, nor in deciphering the mysterious inscriptions on its sides. As far back as 1886, Dr. Le Plongeon published his alphabetic key to the Maya hieroglyphs, comparing this with the ancient Egyptian hieratic alphabet. He has now found that the signs on the Pyramid of Xochicalo are both Maya and Egyptian; and a careful study of these decorative inscriptions has made it plain to him that the pyramid was a monumental structure erected to commemorate the submergence and destruction of the great Land of Mu (Plato's Atlantis), together with its population of 64,000,000 of human beings, about 11,500 years ago.

Le Plongeon was fooled by his own ignorance: Mistaking central Mexican characters for Maya, he imagined a connection that did not exist between the differences in central and southern Mexican writing and Egyptian characters. Unaware of the true age of the Mexican sites, thousands of years younger than Egypt, he imagined them coeval with Egypt. The date, so specific at 11,500 years ago, derives entirely from Plato, applied only because of the assumption that Egyptian writing existed in central Mexico and proved a connection to Atlantis.

But the key to why such theories found audiences (and still do today) can be seen in the first paragraph, where the writer remarks that Americans will be proud to lay claim to an ancient site older than any known in far-off Europe, making America on par with its Old World competitor. Cultural politics trumped reasoned fact, as, sadly, such appeals continue to do today. (Compare with Graham Hancock's equally fictitious 7,000-year-old Mexican pyramid, another mis-dated through ignorance.)

Have you read "Romancing the Maya" by R. Tripp Evans? Besides giving a nice brief history of Le Plongeon and the other 19th cen. explorers, one of his main themes is the appropriation of Central American ruins as "our" ruins by US nationalists.